.content{
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-overflow-scrolling: touch;
  overflow: scroll;
  z-index:1;
}
.btn_join,.btn_join2{
  width:86%;
  height:1.5rem;
  background: url('https://hnres.etalk365.com/app/image/activity_pic/btn_over.png');
  background-size: contain;
  background-repeat: no-repeat;
  position: fixed;
  bottom: 0;
  left: 7%;
  z-index:4;
}
.btn_join2{
  background: url('https://hnres.etalk365.com/app/image/activity_pic/btn_join_success.png');
  background-size: contain;
  background-repeat: no-repeat;
}
img{
  font-size: 0;
  display: block;
}
